A conventional change-gear transmission system is described in US 2012/0245810 claiming priority to DE 10 2009 045 091 A1. In the coasting mode, the torque transmission in the drive train from the engine to the running gear is interrupted by opening a clutch. In the gliding mode, the engine is additionally switched off. When the driver of a vehicle takes his or her foot off the accelerator pedal, an automatic switching of the transmission system into one of these modes makes possible an energy-saving locomotion, with which the vehicle is not decelerated by the drag moment of the engine.
Currently, such an automatic switching is only supported in conjunction with automatic transmissions or automated change-gear transmissions since the speed of the vehicle can change during the coasting or gliding mode and for leaving the coasting or gliding mode, it can therefore be necessary to adapt the gear engaged in the transmission. When leaving the coasting or gliding mode, a gear may be selected for a maximum acceleration, maximum engine braking effect or for low-consumption operation depending on the choice of the driver.
However, such a gear adaptation simultaneously delays the return into the normal driving mode. In particular, when driving in dense city traffic where traffic lights and vehicles driving ahead require frequent and rapid speed adaptations, such an automatic switching forces frequent use of the brake which may be perceived as annoying by drivers accustomed to using a manual change-gear transmission and utilizing the engine drag moment for decelerating the vehicle.
Accordingly, there is a need to provide a change-gear transmission system which on the one hand is able to utilize the fuel savings potential connected with automatic switching into the coasting or gliding mode, and on the other hand is able to make speed adaptations in city traffic without excessive use of the brake.